1. Field of the Invention
The present invention relates to an improvement in a wheel structure for a saddle-ride type vehicle in which a spoke part of the wheel includes a disc attachment boss part.
2. Description of Background Art
For motorcycles including a wheel formed of a hub part, spoke parts extending from the hub part to the outside, and a rim part connecting leading end portions of the respective spoke parts, a wheel structure is known wherein the spoke parts of the wheel includes disc attachment boss parts for attaching a brake disc thereto. See, for example, Japanese Patent Application Publication No. 2008-030648, FIGS. 5 and 7.
In FIG. 5 of Japanese Patent Application Publication No. 2008-030648, a wheel (400) (the number in parentheses indicates reference numeral described in Japanese Patent Application Publication No. 2008-030648. The same shall apply hereinafter) is formed of a hub part (402), multiple spoke parts (411) radially extending from the hub part (402), and a rim part (410) connecting leading end portions of the multiple spoke parts (411). A disc attachment boss (420) is provided standing on one side of each of the spoke parts (411) at a middle thereof. Moreover, a reinforcing rib (430) is provided between each of the disc attachment bosses (420) and the hub part (402).
In FIG. 7 of Japanese Patent Application Publication No. 2008-030648, since the reinforcing rib (430) is provided between the disc attachment boss (420) and the hub part (402), the rigidity of the spoke part (411) is increased. The increased rigidity of the spoke part (411) hardly allows the spoke part (411) to be twisted when a braking force is applied to a brake disc and a force is applied to the disc attachment boss (420).
However, the structure of Japanese Patent Application Publication No. 2008-030648 has the following problems with the reinforcing rib (430) provided between the disc attachment boss (420) and the hub part (402). More specifically, the reinforcing rib (430) increases the weight of the wheel and also increases the material cost.